Tier III compliant high pressure SCR successfully tested

High-pressure SCR system jointly developed by Winterthur Gas & Diesel Ltd and Hudong Heavy Machinery Co Ltd. The cylindrical SCR reactor unit is located in the exhaust duct from the engine cylinders to the turbocharger turbine inlet

MARCH 16, 2015 — The first Wärtsilä two-stroke engine with a high pressure SCR (Selective Catalytic Reduction) system manufactured in China has been introduced.

The system is fitted to a 5-cylinder Wärtsilä RT-flex58T-D two-stroke, low speed engine produced at the Hudong Heavy Machinery Co Ltd (HHM) facilities. The SCR reactor was also manufactured by HHM and, according to Wärtsilä, is the first SCR system to comply with IMO Tier III regulations for engine emissions of nitrogen oxide (NOx).

The SCR equipped engine is to be installed in a new 22,000 dwt multi-purpose vessel currently under construction at China’s Ouhua shipyard for China Navigation Co (CNCo). The ship is scheduled for delivery in the second quarter of this year. It has been designed to allow sufficient space for the fitting of the SCR, enabling the vessel to comply with the Tier III regulations.

The SCR system for this application has been jointly developed by HHM and Winterthur Gas & Diesel (WinGD), the joint venture company of Wärtsilä and China State Shipbuilding Company (CSSC).It uses a basic design concept from Wärtsilä that has been adapted to suit the particular requirements of the engine and ship.

Wärtsilä has been producing its high pressure NOx Reducer SCR systems since the late 1990s. The system injects a solution of urea into the exhaust gas flow to react with and eliminate the NOx emissions. It is a high pressure process because the reactor is located between the engine exhaust valves and the turbocharger turbine inlet. This provides the most compact and efficient system without compromising engine performance or impacting fuel consumption.

“WinGD is committed to an ongoing testing and improvement programme on all areas of Tier III compliance,” said Andrew Stump, Vice President Product Management at WinGD, at a ceremony held earlier this at the factory of CSSC-MES Diesel (CMD) in Lingang, Shanghai, where the system was tested.

The test bed trials were approved by Lloyd’s Register.

“These trials show that the technology to produce IMO Tier III compliant engines is actually available and hence give confidence that IMO Tier III certified engines will be ready for January 1, 2016,” said John Bradshaw, Principal Technical Specialist, Lloyd’s Register.